Trajectory control for directional cluster wells in Ar’er Field

Using directional cluster wells to develop Ar’er depression zone of Huabei Field, according to the geological structure characteristics. The wellbore profile is designed with three sections. The unfavorable factors for developing the zone includes a lot of interbeds, high dip angle, high drilling speed for upper vertical wellbore section, and deviating easily, therefore the trajectory control is difficult, which extends the drilling period and limits the development speed. In the zone, the application of cluster wells request quite a few wells with high well density, and dragging distance of 5~8 m. There are many factors leading to cross-hole collision, so it is difficult to bypass obstacles. Furthermore, the BHA friction and torque are great, and it requires a high level for trajectory control and monitoring techniques. In drilling process, the directional profile optimization technique and the wireless MWD direction and monitoring are taken to adjust timely well trajectory, which guarantees the proper trajectory, and decreases the eccentric wear effect from weighted pump rods used later.